The present invention relates to an arrangement for cleaning fuel with an electrical water level indicating device.
Such an arrangement was proposed in older patent applications, such as patent application Ser. No. 364,670, in which a funnel-shaped deflecting member forms in the interior of a housing an annular gap which extends between a fuel supply and a fuel discharge. A rod-shaped impulse generator is arranged centrally in a cover of the housing and extends through the deflecting member with its free end into a water storing chamber located under the deflecting member. A float which performs two functions is located in the water storing chamber. The float is both a part of an electrical water level indicating device, and also a part of a water discharge device. A permanent magnet is received in a central blind guide hole of the float and cooperates in the event of maximum water level with the impulse generator. The float also has a central spherical closing surface with which during water discharge it throttles the discharge of water via the outlet opening in the bottom of the housing and finally closes this opening. Although the one-piece float performing both functions is simple and inexpensive, it can lead in various applications to the disadvantage that the float with its outer circumference is guided in the bucket-shaped housing part. When the housing is damaged from outside, the float can be clamped and therefore its functions can be endangered. Further, the synthetic plastic material of the float can swell in certain fuels and in dependence on temperature, and thereby its friction in the guide increases, which can eventually lead to undesirably affecting of its functions. Such tilting of the float in the housing can further lead to the situation in which during the water discharge the water discharge opening is throttled by the float too fast and fuel can exit. Furthermore, the known arrangement has no ventilating valve.
U.S. Pat. No. 2,400,200 describes an oil filter in which a manually activated valve controls, in addition to the supply and the discharge for the filter, a ventilating conduit with a valve, and an outlet opening to a dirt collecting container. For discharge of dirt from a sump of the oil filter via the outlet opening into the dirt collecting container, the handactuated valve is opened, and it simultaneously blocks the supply and discharge for filter and the ventilating conduit. In this construction dirt can be removed safe from the filter which is under pressure. However, the filter does not have a float which simultaneously forms a part of a water level indicating device and a throttle valve.